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          <div class="quiz-container">
            <div class="quiz-header">
              <h1>MQ的应用场景 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
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        const quizData = [
  {
    "question": "根据文档，消息队列（MQ）在分布式系统中实现“系统解耦”的核心机制是什么？",
    "options": [
      "通过强制所有组件使用相同的通信协议来增强耦合。",
      "通过消息中间件，让生产者和消费者异步通信，无需直接相互依赖。",
      "将多个服务合并为一个单体应用，从而消除组件间的通信。",
      "为每个服务创建一个独立的数据库，以实现数据隔离。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档明确指出，消息队列通过异步通信机制，允许消息的发送者（生产者）和接收者（消费者）之间不存在直接的交互和依赖。这种方式降低了系统组件间的耦合度，提升了系统的灵活性和可维护性。",
    "source": "文档中「系统解耦」-「异步通信」和「事件驱动架构」部分",
    "hint": "思考一下，当生产者发送消息后，它是否需要等待消费者的回应？这种模式如何影响它们之间的关系？"
  },
  {
    "question": "文档中描述的“流量削峰填谷”功能，其主要目的是什么？",
    "options": [
      "在流量低谷时主动创造请求，以保持服务器的活跃状态。",
      "分析并预测未来的流量高峰，以便提前扩容服务器。",
      "通过充当缓冲层，平滑处理突发的高并发请求，防止后端服务因超负荷而崩溃。",
      "实时拒绝超出系统处理能力的请求，以保护核心服务。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "“流量削峰填谷”的核心思想是利用消息队列作为缓冲区。当面临秒杀或促销活动等场景下的瞬时高流量时，MQ可以先将所有请求接收并存入队列，后端服务再按照自己的处理能力平稳地从队列中拉取任务进行处理，从而避免了流量洪峰直接冲击后端系统导致其崩溃。",
    "source": "文档中「流量削峰填谷」部分",
    "hint": "想象一个水库在大暴雨时所扮演的角色，它是如何保护下游免受洪水冲击的？"
  },
  {
    "question": "在消息队列的体系结构中，哪个组件的主要职责是“负责接收、存储和转发消息”？",
    "options": [
      "生产者 (Producer)",
      "消费者 (Consumer)",
      "消息队列 (Broker)",
      "监控代理 (Monitoring Agent)"
    ],
    "correctAnswerIndex": 2,
    "explanation": "文档定义了MQ的三个主要组件。其中，消息队列（Broker）是核心的中间件，它扮演着消息中转站的角色，负责从生产者接收消息，进行存储（通常是持久化），并根据规则转发给消费者，是确保消息可靠传递的关键。",
    "source": "文档中「消息队列的概念」-「2. 主要组件」部分",
    "hint": "在生产者和消费者之间，需要一个“中间人”来管理消息的传递，这个“中间人”是谁？"
  },
  {
    "question": "为了确保消息在系统故障后不会丢失，消息队列通常采用哪种关键技术？",
    "options": [
      "消息压缩，减小消息体积以加快传输。",
      "消息持久化，将消息写入磁盘进行保存。",
      "消息加密，确保消息内容在传输过程中的安全。",
      "内存缓存，将消息存储在内存中以获得极快的读写速度。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "消息持久化是实现可靠消息传递的核心机制之一。通过将消息写入磁盘，即使消息队列（Broker）发生宕机或重启，存储在磁盘上的消息也不会丢失，待系统恢复后可以继续被消费。相比之下，仅存储在内存中的消息会在断电后丢失。",
    "source": "文档中「可靠消息传递」-「消息持久化」部分",
    "hint": "思考一下，如果服务器突然断电，内存中的数据和硬盘中的数据哪个能被保留下来？"
  },
  {
    "question": "在处理例如“订单创建30分钟后未支付则自动关闭”这类业务场景时，应使用消息队列的哪种特性？",
    "options": [
      "两阶段提交（2PC）",
      "发布-订阅模式",
      "延迟任务（延迟队列）",
      "ACK确认机制"
    ],
    "correctAnswerIndex": 2,
    "explanation": "这种需要在指定时间之后才执行的任务被称为延迟任务。文档中提到，一些MQ系统支持延迟队列功能，可以将消息设置为在特定时间（例如30分钟）后才能被消费者获取。这非常适合用于处理订单超时、定时提醒等场景。",
    "source": "文档中「任务调度」-「延迟任务」部分",
    "hint": "我们需要一个机制，让消息不是立即被处理，而是“等待”一段时间。这个机制叫什么？"
  },
  {
    "question": "文档中提到的“事务消息”（以RocketMQ为例）是如何帮助实现分布式事务的？",
    "options": [
      "它将多个数据库操作打包成一条消息，由MQ原子性地执行。",
      "它要求所有消费者必须在同一时间点完成消息处理并一起提交。",
      "它采用“预处理-执行本地事务-提交/回滚”的两步操作，确保消息发送与本地事务的原子性。",
      "它在发送消息前会锁定所有相关系统的资源，处理完毕后才释放。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "事务消息机制通过将消息发送过程分为两个阶段来确保本地事务与消息发送的一致性。生产者首先发送一个“预处理”或“半消息”，这个消息对消费者不可见。然后生产者执行本地事务。如果本地事务成功，则提交该消息，消费者便可消费；如果本地事务失败，则回滚该消息。这样就保证了“本地事务成功，消息一定发送成功”的原子效果。",
    "source": "文档中「可靠消息传递」-「事务支持」部分",
    "hint": "这个机制的关键在于，消息的最终“可见性”取决于本地操作是否成功。"
  },
  {
    "question": "在消费者处理消息的场景中，ACK确认机制（Acknowledgement）起到了什么关键作用？",
    "options": [
      "消费者用它来向生产者确认消息格式的正确性。",
      "在消费者处理完消息后，向MQ发送确认信号，MQ据此才将消息从队列中删除。",
      "MQ在发送消息前，必须先收到消费者的ACK请求。",
      "它是一种流量控制机制，用于告诉MQ减慢消息发送速度。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "ACK确认机制是保障消息至少被成功消费一次的重要手段。消费者在成功处理完一条消息后，会向MQ发送一个ACK信号。MQ只有在收到这个信号后，才会认为该消息已被成功处理，并将其从队列中移除。如果在规定时间内未收到ACK（可能因为消费者崩溃或处理失败），MQ会认为消息未被成功处理，并会将其重新投递给其他消费者。",
    "source": "文档中「可靠消息传递」-「消息持久化」部分",
    "hint": "如果没有这个“回执”，消息中心如何知道任务是否已经真正完成了呢？"
  }
];
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                '<div class="score-card">' +
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                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  